1. Field of the Invention
This invention relates to a remote control method for an audio/visual system wherein a plurality of units of audio/visual equipment are connected to each other by way of a domestic digital bus system such as, for example, a D2B bus system and also to a system feature starting method and a controlling method for an audio/visual system of the type mentioned. The system feature herein denotes a feature whose operation is performed by cooperation of a plurality of audio/visual units.
2. Description of the Related Art
Audio/visual systems wherein a plurality of units of audio/visual equipment are connected to each other by way of a bus system to make up a set are conventionally known. In an audio/visual system of the type mentioned, a center equipment is set in advance, and one concentrated remote control signal transmission means called system remote controller is provided for a system feature which is executed by cooperation of a plurality of units of equipment. A command from the system remote control signal transmission means is received by the center equipment and the system feature is started, and then, execution of the system feature is controlled by the center equipment. Then, the command or a corresponding command is transferred to the audio/visual equipment.
An exemplary one of the conventional audio/visual systems of the type mentioned is shown in FIG. 8. Referring to FIG. 8, the audio/visual system includes a television receiver 1, a video tape recorder 2, an audio/visual amplifier 3, and a multi-disk player 4 which can reproduce optical disks such as a CD (compact disk) and an LD (laser disk). In the audio/visual system shown, the television receiver 1 serves as a center equipment.
For transmission and reception of an audio signal and a video signal, the television receiver 1 and the audio/visual amplifier 3 are connected to each other by way of an audio/visual signal line L1, and the audio/visual amplifier 3 and the video tape recorder 2, and the audio/visual amplifier 3 and the multi-disk player 4 are connected to each other by way of audio/visual signal lines L2 and L3, respectively.
Further, each of the units of audio/visual equipment 1 to 4 includes a control circuit in which a single or a plurality of microcomputers for controlling operation of the equipment are employed, and the control circuits of the audio/visual equipments 1 to 4 are connected in cascade connection by way of bidirectional buses B1, B2 and B3 for transmission of a control signal into a single system.
The audio/visual equipment 1 to 4 include remote controller receiver sections R1, r2, r3 and r4, respectively, and a remote control signal (command) received by each of them is input to and processed by a control circuit of the audio/visual equipment. In the audio/visual system shown, the remote controller receiver section R1 of the television receiver 1 is used only for reception of a signal from system remote control signal transmission means CM1. A command to execute a system feature which is performed by cooperation of a plurality of units of audio/visual equipment is transmitted from the system remote control signal transmission means CM1 to the remote controller receiver section R1 of the television receiver 1. The television receiver 1 converts the command received from the system remote control signal transmission means CM1 into a bus command (a command to be transmitted to each unit of audio/visual equipment by way of the bus system) and sends out the bus command to the audio/visual equipment by way of the buses B1 to B3.
Each unit of audio/visual equipment transfers the bus command to a next unit of audio/visual equipment and determines whether or not the address included in the bus command is an address representative of the unit of audio/visual equipment itself, and then, if the address is the address of itself, the bus command is fetched and decoded so that an operation corresponding to the command is executed.
In the audio/visual system of FIG. 8, commands from the different system remote control signal transmission means are all received by the television receiver and a bus command is delivered to the equipment, but the television receiver includes the receiver section only and does not function as a system controller which controls the entire system. It is to be noted that the system remote control signal transmission means CM1 also generates a command of a feature whose operation completes itself only with the television receiver 1.
Further, in the audio/visual system of FIG. 8, remote control signal transmission means cm2, cm3 and cm4 for exclusive use are prepared for the individual audio/visual equipment 2 to 4, respectively, and each unit of the equipment 2 to 4 itself can uniquely receive also a command from the remote control signal transmission means cm2, cm3 or cm4 for exclusive use therewith.
FIG. 9 shows another exemplary one of the conventional audio/visual systems of the type described above. The audio/visual system is constructed such that audio/visual equipment other than a center equipment are connected in a star connection around the center equipment so that one directional communication is performed from the center equipment. In particular, in the audio/visual system, a system controller 5 is provided as a center equipment, and a video tape recorder 6, an audio/visual amplifier 7, a multi-disk player 8 and a television receiver 9 are connected to the system controller 5 by way of one-directional communication control lines W1, W2, W3 and W4 so that they are controlled one-directionally by the system controller 5.
The audio/visual amplifier 7 and the television receiver 9 are connected to each other by way of an audio/visual signal line L4, and the audio/visual amplifier 7 and the video tape recorder 6, and the audio/visual amplifier 7 and the multi-disk player 8 are connected to each other by way of audio/visual signal lines L5 and L6, respectively. The audio/visual system further includes an extended second video tape recorder 10, which is not compatible with the one-directional communication of the audio/visual system.
System remote control signal transmission means CM2 is provided for a receiver section R5 of the system controller 5, and a command of a system feature is transmitted from the system remote controller CM2 to the system controller 5. When the command of the system feature is received, the system controller 5 transmits a control command to the equipment 6 to 9 by way of control lines W1 to W4 to realize the object system feature.
Also in the present audio/visual system, the audio/visual equipment 6 to 9 and the extended equipment 10 can receive, at respective receiver sections r6 to r9 and r10 thereof, commands from remote control signal transmission means cm6 to cm9 and cm10 for exclusive use therewith, respectively, and execute features they individually have.
In the audio/visual system, audio/visual equipment to be newly extended are limited by the number of plugs or jacks of the system controller 5 serving as center equipment or the number of selection keys for categories (for example, a video tape recorder or a multi-disk player) of system remote control signal transmission means. When an audio/visual equipment to be extended is a product of a different company, any of a very limited number of commands of the system remote control signal transmission means is converted in the inside of the system controller 5 serving as a center equipment and transmitted to the audio/visual equipment or else a code of the different company is transmitted directly to the equipment from the system remote control signal transmission means.
With the conventional audio/visual systems described above, however, no protection means for a system feature during execution of the system feature is involved, and even if the system feature has been started with the center equipment set as a master and is being executed, if a command from the remote control signal transmission means for exclusive use with any of the units of equipment is received, then the audio/visual system operates unconditionally in response to the command.
For example, when the multi-disk player 4 or 8 receives a stop command from the remote control signal transmission means cm4 or cm8 for exclusive use therewith while dubbing wherein a reproduction signal of the multi-disk player 4 or 8 is being recorded the multi-disk player 4 or 8 enters into a stop mode although it is performing dubbing. Therefore, there is the possibility that the video tape recorder 2 or 4 may maintain its recording condition without knowing that the multi-disk player 4 or 8 has stopped.
Also with the conventional systems, when each of the unit of audio/visual equipment recognizes a system feature being executed thereby or when any units of the audio/visual equipment delivers an inquiry for a feature being executed to the center equipment, the feature being executed can be recognized and protection for the feature can be performed. In this instance, however, there is a problem in that a large memory capacity is required for each audio/visual equipment or confusion of communication on the bus results. Further, where a warning indication such as, for example, "during execution of dubbing at present" is provided for protection, such indication must be performed on each of the audio/visual equipments. Consequently, each of the units of equipment is complicated in construction.
Further, the conventional audio/visual system of FIG. 9 has a drawback in that it is difficult for a user to recognize or operate the system in that the controlling method for an extended equipment is unclear or the matching method is varied depending upon the manufacturer.
Further, in the conventional audio/visual systems, when infrared rays are used for a remote controller signal, the remote control signal transmission means for exclusive use with each of the equipments must necessarily emit a remote controller signal toward the corresponding audio/visual equipment, but since a plurality of remote control signal transmission means are present and because the positions of the remote controller receiver sections are generally different among the individual units of audio/visual equipment, there is the possibility that confusion by which remote control signal transmission means and to which direction a remote controller signal should be emitted may result.
On the other hand, in the conventional audio/visual systems, when a command is to be transmitted from the system remote control signal transmission means to the center equipment to perform a system feature, the user will perform also an operation to select audio/visual equipment, with which the system feature is to be executed, by way of a selection key (switch) of the system remote control signal transmission means.
A further audio/visual system is also known wherein a system feature is started in response to a trigger signal other than an operation of such system remote control signal transmission means. In particular, the audio/visual system is constructed such that a variation when a power source switch of each equipment is operated to make the power source available is detected by the audio/visual center equipment and, in response to such detection, the audio/visual center equipment automatically performs switching of a source. Where the audio/visual equipment is, for example, a CD player, when the power source to it is turned on, the audio/visual center equipment detects the variation and connects the reproduction output of the CD player to a loudspeaker by way of an audio/visual amplifier to effect switching of the source.
In the conventional audio/visual system described above, an equipment with which a system feature is to be performed must be selected by means of the system remote control signal transmission means. Meanwhile, in recent audio/visual systems, a plurality of video tape recorders, disk reproduction apparatus and so forth can be connected. Therefore, each of the systems remote controllers includes a plurality of selection keys provided for the category such as a video tape recorder, and one of the units of audio/visual equipment must be specified by selection using a plurality of selection keys provided for each category. Consequently, operations are complicated, and the user is puzzled frequently in operation.
Further, with the conventional audio/visual system, while only one unit of equipment to serve as a source can be determined from within a plurality of units of equipment, such a complicated operation as to alternately switch two sources is not available.
Further, the conventional audio/visual system is further disadvantageous in that the range of application of a system feature is so small that, even if it is tried to add a new system feature to an audio/visual equipment to be incorporated newly into the audio/visual system, since the audio/visual center equipment controls all system features, such addition cannot be realized unless the audio/visual system recognizes the new system feature in advance.